Created options file.
Added 'cookieExpireTime' to configuration file.
Major overhaul to the header modal, now works with cookies.

'checkAutoFind' is stored in a cookie.
Prohibited direct access to config file.
Added error message to index page if 'header.php' doesn't exist.
Added error message to header page if 'header_comment.php' doesn't exist.
Added error message to gallery page if 'header.php' doesn't exist.